Apremilast, which is chemically known as N-[2-[(1S)-1-(3-ethoxy-4-methoxyphenyl)-2-(methylsulfonyl) ethyl]-2,3-dihydro-1,3-dioxo-1H-isoindol-4-yl]acetamide is represented by a compound of formula I,

Apremilast marketed as OTEZLA® is a tablet available in multiple strengths for oral administration and is indicated for the treatment of adult patients with active psoriatic arthritis.
Various synthetic processes for preparation of apremilast are known in the art. The present invention provides a process for preparation of apremilast wherein a non-carboxylic acid solvent is used in the condensation of compound of formula II with compound of formula III or salt thereof which provides apremilast with better purity profile and which can be easily performed on industrial scale.